No -- there's no need to add any oil when boiling pasta. Just use lots of water and salt it generously -- it should taste of seawater. Bring the water to a rolling boil and add the pasta and it shouldn't stick together.

Not unless you want greasy spaghetti. Some people worry that strands will stick together. But the way to finish your dish is to scoop the pasta from the boiling water (don't drain it) and transfer it directly to the sauce in which it will be presented.

Definitely no oil and no way a whole cup! Agree with all that has been said above. A couple of additional thoughts: poor quality pasta and over-cooking pasta both contribute to stickiness, as well. If you are doing a cold pasta, like for a pasta salad, you'll want to shock it in ice water when it's done, then drain it.

Oil in pasta water is a no-no. It keeps the sauce from grabbing onto your noodles, among other things. Boiling water and lots of salt is the way to go. Stir frequently to prevent sticking, cook to al-dente, drain and add them to your sauce to finish cooking and marry flavors. Maybe a drizzle of oil to finish..... :) Good luck!